Method of purging thermostats



April 23, 1940.

L. M. PERSONS 2,198,561

METHOD OF PURGING THERMOSTATS Filed Sept. 11, 1937 ill- //v vim/roe.- Lewes/m5 1% psesolvs,

Bra wi w Patented Apr. 23, 1940 UNITED STATES PATENT signor to Automatic Control Corporation, St.

Louis, Mo., a corporation of Delaware Application September 11, 1937, Serial No. 163,452

7 Claims.

The present invention relates to a method of filling thermostats and especially thermostats requiring the complete elimination of all the air present therein.

It has heretofore been proposed to accomplish this by centrifugal means. The present application deals with such a centrifugal means but with certain improvements permitting its use with tubes of extra length and with thermostats having chambers such as expansion means on both ends.

It is, therefore, a broad object of the invention to provide a method of filling thermostats of extra length, and an additional object to provide such a method for filling thermostats having chambers such as expansible means at opposite ends of a single tube.

It is a further object of the invention to provide a method of filling thermostats by elimination of air at an intermediate point of the tube.

In the drawing:

Fig. 1 shows an elevation partly in section of a machine for accomplishing the method;

Fig. 2 is a horizontal section of one of the arms of the machine;

Fig. 3 is an enlarged sectional view of a portion of the head on one of the arms;

Fig. 4 is a section of the inner point of the tube at which the air is discharged; and,

Fig. 5 is a view similar to Fig. 4 but showing the tube sealed.

The machine here shown is similar to that of copending application, Serial Number 116,700, filed December 19, 1936, by the present inventor, reference being made to that case for any details not here given.

In Fig. 1, there is shown a motor l0 supported by a base II and having a housing l2 therearound. The motor has a rotating shaft I3 to which is secured an extension l4 supported on the housing l2 through the means of a frictionless bearing l5. At the top end of the extension H are provided pairs 16 of spaced ears, two of which are shown more clearly in Fig. 2. A plurality of arms I! are provided with tongues l8 that fit within the spaced ears I6 and are bolted therein by bolts 19 about which they may pivot. Preferably square shoulders 20 on the tongues limit the downward pivotal movement to approximately that shown in Fig. 1.

The arms are hollow and preferably are streamlined by being rounded on their leading edges and flared out as at 2| on their trailing edges.

To the outer ends of the arms are secured heads, generally indicated at 22. Each head consists of an inner section 23 secured to the outer end of the arm I! and an outer section 24 pivoted at 25 to the inner section. A lock means 26, described in my copending application abovementioned, is provided releasably to hold the outer section 24 close against the inner section 23.

Each inner section is provided with a plurality of cup-shaped seats 28 spaced circularly thereabout. Each seat has a radial tube-receiving 10 passage 29 extending inwardly therefrom. Opposite the central portion of the seats 28 are plugs 30 secured to the outer section 24 for a purpose to be described. A mandrel 3! is located within the hollow arm I! and is designed to abut 15 outwardly against the section 24 of the head. The mandrel has a plurality of spiral grooves 32 around its surface. v

The present method finds particular application to thermostats of the diaphragm type, al- 20 though, obviously, it is of broader scope. In the drawing a thermostat having two such diaphragms 33 and 34 is shown. Each diaphragm consists of an outer cup-like member 35 and an inner flexible cup-like member 36, the two being .25 secured together around their circular sides. Each outer cup, at one corner, receives the end of a fluid conducting tube, such as 31 or 38, generally of capillary type. The tubes thus communicate to the area between the cup 35 and the .3 diaphragm 36. The two tubes are spirally wound around the mandrel 3| with a sufficient number of turns so that the entire length of the two tubes can be accommodated within the arm I! and yet preserve always a continuous progression of the tubes outwardly from their inner limit within the arms. At their inner extremities, the two tubes 3! and 38 enter a larger tubular element 40 and are sealed therein, as by solder 4|.

In position, the axis of each cup extends at an angle to a radius of rotation, with a plane perpendicular to the cup axis extending outwardly at an angle from such radius. The tubes extend continuously inwardly from the innermost point of the cup to the tubular element 43.

In practising the method, a suitable number of pairs of thermostats are arranged with their tubes wound in the grooves 32, their ends joined in element 40. At this time the tubes are filled E50 with the thermostat fluid up to a point near the open end of the tubular element 40. The assemblies and mandrels are inserted in the arms, and thecups are seated within the seats 28 of the inner section 23 of the head. The mandrels fit v,55

rather closely within the arms, so as not to move much when in place. The outer section 24 is closed down, bringing the plugs 30 tightly against the diaphragms 35, thus preventing the diaphragms from moving outwardly under centrifugal action. The motor ii! is then started rotating the arms. The centrifugal force set up lifts them about their pivots 19 until they are horizontal. Because of the angular arrangement of the seats 28, the fact that the tubes 31 enter the diaphragms at their innermost points when the diaphragms are located in the seats, and the fact that thespiralling of the tubes produces in them. a. continuous outwardly progressing path, causes the liquid. to

be forced as far outwardly in the assembliesas possible, displacing the lighter air from the remotest crevices about the diaphragm into the tubes and ultimately out the open endv of the tubular element 40.

After the centrifuging has gone on for a sufiicient length of time, the motor I is stopped and the tube assemblies removed. The enlarged element dll'is then crimped as shown in Fig. at 42 and its open end sealed with solder 43. Any excess length may be removed. The tubes may then be stretched apart as necessary and the system is thus formed having a thermo-responsive element at each end and with the air entirely removed.

Although a system has been shown having a thermal element at its opposite ends, it is to be understood that the device, manifestly, is to be used for any similar arrangement wherein it is desired to eliminate a lighter substance at some middle point of an elongated system. Furthermore, the use of the mandrel and the coiling of the tubes may be used with a system such as is embodied in one tube and one thermal element,

thereby saving much in the length of the centrifugal arms.

What is claimed is:

1. In a method of purging assemblies filled with a heavy and a light substance, having a hollow connecting means between two chambers, the

steps of maintaining the two chambers outwardly from a given axis, and an intermediate point of. the. connecting means between the chambers inwardly toward said axis, with the parts of the said means at each side of said intermediate. point extending continuously outward from the point, relativev to the axis, to the respective chambers, and rotating the assemblies about the axis, to cause the heavy substance to displace the lighter centripetally from both chambers and the connecting means to said intermediate point.

2. In a method of eliminating a light fluid from assemblies having a pair of chambers connected by a tube means, and adapted to be filled with a heavy fluid, the steps of maintaining the two chambers outwardly from a given axis, and an intermediate point of the tube means between the chambers inwardly toward said axis, with the parts of the tube means to the sides of the intermediate point extending continuously outwardly, relative to the axis, from the point to the respective chambers, and with the tube means at the intermediate point. open, rotating the assemblies about the axis to force by centrifugal pressurev of the heavier fluid the light fluid inwardly from the chambers and tube means to the opening of the latter, and finally sealing the tube means inwardly from the opening.

3. In a method of eliminating a light fluid from assemblies adapted to be filled with a heavy fluid and having a pair of chambers with a tube extending from each, the steps of maintaining the chambers outwardly from a given axis with the two tubes extending continuously inwardly toward said axis, with their innermost ends adjacent each other, providing a sealable receiving element over the open adjacent ends of the tubes, rotating the tubes about the axis to cause centrifugal force upon the heavy fluid to discharge the lighter fluid centripetally out the chambers through the tubes and from the open ends of the tubes, and after such rotation, sealing the receiving member to maintain the tubes in communication with each other, and to prevent ingress of the lighter fluid into the assembly.

4. In a method of eliminating fluid from assemblies adapted to be filled with a heavy fluid, said assemblies consisting of a pair of cup-like members each having a diaphragm sealed to it, and a tube extending from one corner of each cup-like member, the steps of maintaining, the cup-like members with their tubes. inwardly to.- ward an axis of rotation and a plane across the cup axis extendingat an angle outwardly from a radius to the axis of rotation, extending the tubes continuously inward. toward the axis of rotation and with their open ends: adjacent, providing an enlarged tube over saidopen ends, it being open at its end remote from the tubes, rotating the assemblies about said axis of rotation to cause the lighter fluid to be discharged from the cuplike members into the tubes, along the tubes, and out the enlarged tube by'centrifugal force on the lighter fluid, leaving the heavier fluid filling the assemblies entirely including at least a portion. of the enlarged tube beyond theends of the smaller ones, and finally sealingthe enlarged tube between its open end and the smaller tube ends,

and within that portion of the enlarged tube containing the heavier fluid.

5. In. a method of eliminating light fluid. from an assembly adapted tobe filled with a-heavy fluid, said assembly including a chamber and a tube extending therefrom, the steps of supporting the chamber soas to extend outwardly from an axis of rotation withno. pockets toward said axis, and with the tube entering at the point on the chamber nearest the axis, winding the tube into a spiral extending continuously inward from the chamber toward the axis of rotation with its open end nearest said axis, and. rotating the assembly about said, axis. to cause centrifugal force on the heavy fluid to discharge the light fluid inwardly from the chamber into the tube, along the tube toward the axis, and out the open end of the tube.

6. In a method of making thermostats to consist of a pair of cup-like members each having a flexible cup-like diaphragm normally contiguous throughout its area with the. member and sealed thereto, and a tube joining the cup-like members, all space between the diaphragms and the cuplike members and in the tube to be filled with thermal liquid, the steps of supporting each cuplike member with a section of tube annexed in such wise. that the cup opens away. from a given axis of rotation with the cup axis non-radial to said axis of rotation and approaching a radius to the axis of rotation outwardly from the axis of rotation, and disposing the tube from the point on the member nearest the axis of rotation spiralled inwardly toward said axis, bringing the open ends of the two tubes in an enlarged tubular element,

tube ends to said ends, rotating the assemblies about the axis of rotation todischarge the air therefrom out the open end of the tubular element, the thermal fluid then filling the entire assemblies including at least part of the tubular 5 element, and finally sealing the open end of the tubular element inwardly beyond the limits of the thermal fluid.

'7. In a method of purging assemblies filled with a heavy and a light substance, having a hollow 10 connecting means between two cup-like chambers, thesteps of maintaining the two chambers relative to an axis of rotation so as to have a plane across each cup axis extending at an angle each side of said intermediate point extending continuously outward from the point relative to the axis to the respective chambers, and rotating the assemblies about the axis, to cause the heavy substance to displace the light substance centripetally from both chambers and the con- 10 necting means to said intermediate point.

LAWRENCE M. PERSONS. 

